From Xen
Revision as of 07:43, 10 November 2011 by Kyl191 (talk | contribs) (Important Tip / Caveat)


PyGrub enables you to start Linux DomUs with the kernels that lie in the filesystem of the DomU instead of with a Kernel that lies in the filesystem of the Dom0. This enables easier kernel update from DomU or migration of HVM'ed Linuxes.


It is used as a Bootloader and provided with Xen. PyGrub behaves like Grub and reads the standard Grub menu.lst (or Grub2's grub.cfg) to provide the xen create process with the required parameters and SXP stanzas.

  • Question is: Does it copy the req'd kernel and initd temporarily out to Dom0 for it to access it there or does Dom0 access the kernel and initd in their filesystem? Anyone?

Therefore usage is quite easy.


In your domU

  1. Install Grub

In your dom0

  1. Change your domU.cfg:
  • remove kernel and initrd stanza
  • add bootloader stanza, e.g. bootloader = '/usr/bin/pygrub'


Important Tip / Caveat

On your disk line, e.g.



Error: Boot loader didn't return any data 

